Tulkens P, Schneider Y J, Trouet A
Acta Biol Med Ger. 1977;36(11-12):1681-90.
A striking feature of endocytosis is the large amount of surface membrane that is brought into the cells through the formation of endocytic vesicles. Little is known about the fate of this membrane material. It is implausible that it would be destroyed in lysosomes, as the rate of turnover of the constituents of plasma membrane is much too low with respect to the rate of endocytosis in all cells studied so far. Conversely, plasma membrane fragments, internalized by endocytosis cannot merely be incorporated in lysosomes, as these organelles have been shown to maintain their size, despite continuous and active endocytosis. We present evidence that plasma membrane antigens, detected by means of specific antibodies, are internalized during endocytosis and reach lysosomes. They are thereafter returned back to cell surface. These results indicate the existence of a shuttle of membrane elements between the cell surface and lysosomes.
内吞作用的一个显著特征是通过内吞小泡的形成，大量的细胞膜被带入细胞内。关于这种膜材料的命运知之甚少。它在溶酶体中被破坏是不太可能的，因为就目前研究的所有细胞的内吞作用速率而言，质膜成分的更新率太低了。相反，通过内吞作用内化的质膜碎片不能仅仅被并入溶酶体，因为尽管存在持续且活跃的内吞作用，但这些细胞器已被证明能保持其大小。我们提供的证据表明，通过特异性抗体检测到的质膜抗原在胞吞作用过程中被内化并到达溶酶体。此后它们又回到细胞表面。这些结果表明在细胞表面和溶酶体之间存在膜成分的穿梭。
